Many do have the sense that somehow photographs represent reality, rather than providing a partially-constructed interpretation of it. (Why do we always come together and smile in photographs? Why do we take photos at weddings but not funerals?) Books are usually understood as entirely constructed; one may agree or disagree with the facts in them, but they aren't seen as reflections of reality in quite the same way.

Hmmm... something seems to be at odds there if people perceive photographs as representing reality while (subconsciously) applying those filters. I don't usually have people pose for photos; I prefer taking snapshots of people doing whatever it is they're doing.

Yep, with the advent of digital cameras candid shots have become much more popular ... people have always said they *like* candid shots but with film they were less willing to put up with lots of bad pictures to get a good few, since they were paying for each picture. (That, and some aren't as willing to give up the control that the posed shot provides, despite liking candid shots. Think especially of family photographs. :~)) But the cameras still only come out at "happy" events and most wouldn't take candid shots of someone hurt or upset (unless it was a more humorous "it's not really so bad!" kind of shot), and ultimately, there's a lot that is left out of every photograph.

The realistic perception of images extends beyond personal photographs: newspaper images, professional pictures, and any sort of photographic representation is assumed to be a "slice of reality" (Sontag says more on this: http://sims.berkeley.edu/~morganya/photography/Sontag_In_Platos_Cave.pdf). When looking at your own personal photographs, you may remember that this event wasn't as happy as the pictures might suggest or these two who were standing next to one another in the picture were actually angry at one another at the time, but those supplemental memories are personal to you and fade over time. (That, and repeated viewing of these pictures can actually morph your memories of the event to better match what's in the pictures.)

Of course, Photoshop throws a wrench in the works, but it seems too early still to say how much that will break down this perception of photos as a slice of reality. Even during the 2004 election photoshopped pictures like the one of Kerry next to Jane Fonda at a peace rally created a furor in the popular media; clearly the majority of the population is still accustomed to trusting the veracity of photographs.

Sorry for the long reply, but I love this stuff - it's so interesting to me! :~)